Phosphonic and phosphinic acid esters and process for their production



United States Patent Cfifice 3,008,977 Patented Nov. 14, 1961 The present invention relates to and has as its objects new and useful insecticidal phosphonic and phosphinic acid esters and processes for their production. The new compounds of the present invention may be represented by the following general formula wherein R and R stand for radicals which are necessary for the formation of phosphonic or phosphinic acid derivatives. X represents an optional radical of an organic sulfhydryl-oontaining compound of the thiocarbonic and thiocarbamic acid group. The compounds of this invention are obtainable by methods known in principle, especially by reacting S-(flbromoalkyl)0.0-dialkyl-thiolphosphoric acid esters with suitable thiolcarb'onic or carbamic acid derivatives as it is to be seen from the following equation: R1 0(8) (S) R1 0 (S) (S) O R H II /P S alkylene- S C-O R- N vent. Acetone has proved to be especially satisfactory as a solvent of this type. It is, however, also possible to use, for example, a mixture of water and aceto-nitrile as the solvent. The reaction can sometimes also be carried out in the presence of alcohols.

The compounds, which are new, obtainable in the aforementioned way are distinguished by a good contactinsecticidal and systemic activity.

As an example for the special utility of the inventitive compounds the compound of the following formula has been tested against aphids. Aqueous dilutions of the aforementioned compound have been prepared by mixing the active ingredient with the same amount of dimethyl formamide as an auxiliary solvent adding thereto 20% by weight referred to active ingredient of a commercial emulsifier consisting of a benzyl hydroxy polyglycol ether containing about to glycol ethers, and diluting at last this premixture with water to the desired concentration indicated in the following paragraph.

The test has been carried out as follows: against aphids of the type Doralis fabae: heavily infested bean plants (Vicia faba) have been sprayed drip wet with solutions as prepared above. The efifect has been determined after 24 hours by counting the dead pests either on the surface of the soil or still remaining on the plants. The following results have been obtained: aphids were killed completely with 0.001% solutions.

The following examples are given to illustrate the present invention.

Example 1 O OCaHa II/ P 40 grams (0.25 mol) of potassium xanthogenate are dissolved in 150 ml. 10f acetone. 62 grams (0.25 mol) of 'S-fi-bromo-ethyl-O-ethyl methyl phosphonate are added with stirring at 40 C. The mixture is heated to 45 for 2 hours and then cooled to room temperature. The reaction product is put into 300 ml. of ice-water. The separated oil is taken up in benzene, washed neutral with water and dried with sodium sulfate. By distilling off the solvent 50 grams of the new ester are obtained as a weakly yellow water-insoluble oil. The ester is not distillable even in high vacuum. Yield: 69% of the theoretical.

By the same way there may be obtained the compounds of the following formulae:

40 (0.25 mol) grams of potassium Xanthogenate are dissolved in 150 ml. of acetone. At 50 C. there are added with stirring 66 grams (0.25 mol) of S-B-bromo-ethyl-O- ethyl ethylphosphonate. Heating is continued for 2 hours at 50 C. followed by working up as described in the previous examples. In this way 48 grams of the new ester are obtained as a yellow water-insoluble oil. Yield: 77% of the theoretical. The ester is not distillable even in a high vacuum.

Aphids are killed completely with 0.01% solutions, spider mites are killed completely with 0.001% solutions and caterpillars are killed to with 0.1% solutions. Systemic action with 0.1% solutions=100%.

By the same way there may be obtained the compounds of the following formulae:

36 grams (0.25 mol) of dimethylamino-d'ithiocarbamic acid sodium salt are dissolved in 150 ml. of acetone; ml. of water are added to the solution and then 66 grams (0.25 mol) of S-fi-bromo-ethyl-O-ethyl ethylphosphonate are added dropwise at 50 C. with stirring. Heating is continued at 50 C. for 2 hours followed by working up in the usual way. 62 grams of the new ester are obtained as a yellow viscous oil. Yield: 82% of the theoretical. The ester is not distillable even in a high vacuum.

Aphids are killed completely with 0.01% solutions, spider mites with 0.001% solutions and caterpillars with 0.1% solutions. Systemic action with 0.1% solutions: 100%.

By the same way there may be obtained the compounds of the following formulae:

36 grams (0.25 mol) of dimethylamino-dithiocarbarnic acid sodium salt are dissolved in 150 ml. of acetone. 5 ml. of water are added to the acetone solution which is then stirred while 62 grams (0.25 mol) of S-B-bromoethyl-O-ethyl methylphosphonate are run in at 55 C.

E The reaction product is held at C. for a further 3 hours and then worked up in the usual way. 57 grams of the new ester are obtained as a yellow water-insoluble oil. Yield: 79% of the theoretical. The ester is not distillable even in a high vacuum.

0.001% solutions kill aphids to and spider mites to Caterpillars are killed completely with 0.1% solutions. Systemic action with 0.1% solutions=l00%.

By the same way there may be obtained the compounds of the following formulae:

X(%Salkylene-SP in which R and R stand for a member selected from the group consisting of lower alkyl radicals having up to 4 carbon atoms and lower alkoxy having up to 4 carbon atoms, alkylene being a lower alkylene group having up to 4 carbon atoms, Y and Z being a member selected from the group consisting of oxygen and sulfur, and X stands for a member selected from the group consisting of lower alkoxy and lower dialkyl-amino-groups, the alkyl radicals having up to 4 carbon atoms.

2. The compound of the following formula H O OC2H5 O2H OCSCHz--CHzS-P OH: I

3. The compound of the following formula 0 001115 II 11/ C H O-CS-OHz-OH SP 4. The compound of the following formula H (")/O CzHa (CHa)zN-CSCH2CH2SP CzH5 5. The compound of the following formula H fi/OCzHs (CHa)zNCSCHzCHzS-P No references cited.

- UNITED STATES PATENT OFFICE CERTIFICATE ()F CORRECTION Patent No. 3,008,977 November 14,- 1961 v Gerhard Schrader 7 It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column l. line 44, for ""$1ulhydryl read su li hyu ryl same column, line 60, for inventitive" read inventive column 2, between lines 50 and 53, the formula should appear as shown below instead of as in the patent:

(SEAL) Attest: ERNEST W. SWIDER DAVID L, LADD Attesting Officer Commissioner of Patents 

1. THE PHOSPHOROUS ESTER OF THE FOLLOWING FORMULA 